Intumescent Letterbox Liners

A self-adhesive backed intumescent material that is coated on one side to reduce wear and which is designed to line the aperture of letterboxes in ½ hour & 1 hour fire resistant door assemblies.

On exposure to heat from a fire the intumescent material swells to many times its original volume producing a fire resistant seal against the passage of fire, smoke and hot gases.

The liner can be used in either existing or new letter boxes and is designed to be used with metal letter plates/tidys which must be fitted to both sides of the door ~ external plate must be sprung, internal must be gravity type.

Tested to BS 476 : Part 22 : 1987

Liners are supplied in Black and Red colours to suit apertures up to 250mm x 50mmMetal plates/tidys are not supplied with liners